Method of preparation of acetaldehyde



G. O. CURME, 1n.

METHOD OF PREPARATION 0F ACETALDEHYDE. APPLICATION FILED )UNE 3. 1916. RENEWED DEC. 12.1911.

1 ,3 1 5, 5 4:3 Patented Sept. 9, 1919.

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UNITED STATES PATENT OFFICE.

GEORGE O. OUBHE, m, 0! PITTSBURGH, PENNBYLVQNIA, ESSIGNOR, BY IKE BITE ASSIGNMENTS, 1'0 UNION CARBIDE COMPANY, OF NEW YOBK, N. Y., A CORPO- RATION' OF VIRGINIA.

METHOD OF PBEPABATIOII OF AOETALDEHYDE.

' Application filed June 8, 1818, Serial No. 101,638.

To all whom it may concern:

Be it known that I, Gnonon O. Gonna, J r., a citizen of th United States, residing at Pittsburgh, A] egheny county,'and State of Pennsylvania, have invented and discovered certain new and useful Improvements in Methods of Preparation of Acetaldehyde, of which the following is aspecification.

Ethylene and a salt ofmercury react in aqueous solution to form a compound of the type HgSO,.C,H,, such as is formed by the inter-action of mercuric sulfate and ethylone in aqueous solution; these compounds being readily soluble in water and acteilitg so as to yield up the ethylene content r ily, offer the possibility of obtaining a considerable concentration of ethylene in the aqueous solution. The ethylene portion of the compoundis above specified is capable of oxidation an by suitable means, can be transformed into acetaldehyde. My present invention, therefore, consists in the method and means for preparin acetaldehyde bythe anodic OXidRtlODQ ethylcne in an electrolytic cell in the presence of a salt of mercury. I

Theaccompanying drawing illustrates an apparatus which is found suitable for the pur se. Said a paratus consists of a cell 10 ormed with d duble walls between which is mounted a heating coil 11. Within the cell is mounted a ring-shaped anode 12 and a cone-shaped diaphragm 13 dividing the cell into an anode chamber above said diaphragm and a cathode chamber below said diaphragm. Said diaphragm terminates at the top in a discharge tube or central outlet 14 for the hydrogen formed simultaneously in the process of electrolysis. An inlet pipe 15 connects with a perforated ring 16 mounted beneath the anode and above the cathode in the cell, and an outlet 17 leads out from the top of the cell or the discharge of acetaldehyde vapors mixed with ethylene leading to condenser, not shown, where acetaldehyde .is removed,

It will be understood, of course, that the apparatus thus illustrated is merely a suggested arrangement, found suitable for the purpose, but may be modified materially as may be desired for varying commercial uses. The cone diaphragm "13 is of porous material pervious to liquids but not to see when wet, and separates the cathode 0 am- Specification of Letters Patent.

Patented Sept. 9, 1919. Renewed December 12, 1917. Serial No. 208,849.'

her from the anode chamber, and both chambers are filled with solutions described be low.

The anode may be of platinum, lead peroxid, magnetite, or other suitable substance such as will not be attacked either by the acid solution or by the oxidizing influence of the anode chamber, and the chamber containin the same is charged with aqueous sulfuric acid from 0-50% concentration and the desired amount of mercuric sulfate, or compound of mercury formin the sulfate when in contact with the acid o the strength giveni smallest to a considerable quantit greater than what will dissolve in the acid of the This amount may vary from the furic acid solution, or, in other manner, is

brou ht into intimate contact with it, and the e ectric current is allowed to pass. The ethylene reacts with the mercury salt, the

subjected to t e oxidizing influence of the anode, where it is oxidized to acetaldeh de,

resulting compound is thus dissolved ahd regenerating the mercury salt in its orig nal condition at the same time.

In this process, the solution is ke t at a temperature between 21 0., the oiling point of acetaldehyde, andthe boiling int of the solution used, under which conditions the acetaldehyde is volatilizedand can be removed from the anode chamber as rapidly as formed. In 001*] practice the amount being furtheroxidized to acetic acid may be kept very small indeed. B a suitable condensing device (not shown the acetaldehyde is condensed out as rapidly as formed, while the eth lene, which may escape with'the acetalde yde va rs, is returned tothe anode chamber or further treatment.

Stirring favors the reaction.

The presence of a certain salt in the anode chamber acts catalytically in favoring the oxidizing reaction. I

The current density on t e anode may vary between wide limits. urrent densities up to 5.0 amperes per square decimeter will give good results and even higher densities may profitably be used. The voltage required is that necessary to pro duce the desired current in any given cell wherethe resistance is a proximately constant. It need not excee 4.0 volts in most cases.

Having thus fully described my said invention, what I claim as new and desire to secure by Letters Patent, is:

1. The process of forming acetaldehyde which consists in combining ethylene with a mercury salt solution, sub ectin the compound thus formed to anodic oxldation in aqueous solution, and removin the acetaldehyde by continuous distillatlon, tially as set forth.

2, The process of forming acetaldehyde which consists in combining ethylene with a mercury salt solution in an electrolytic cell, subjecting the compound thus formed to anodie oxidation, removing the acetaldehyde by volatilization, and condensing the same in a separate chamber, .substantially as set forth.

3. The process of forming acetaldehyde which consists in combining ethylene with a mercury salt solution charged with aqueous sulfuric acid from 0-50% concentration, subjecting the compound thus formed to anodic oxidation, and removing the acetaldehyde by distillation, substantially as set forth.

4:. The process of forming acetaldehyde which consists in combining ethylene with a mercury salt solution at a temperature maintained at a point above the boiling point of acetaldehyde, subjectin the compound thus formed to anodlc oxi ation, and

substansalt in an removing the acetaldeh do by distillation, substantially as set fort 5. The process of forming acetaldehydc which consists in combining ethylene wit a mercury salt solution in an electrolytic cell, subjectin the compound thus formed to anodic oxidation, the anode being composed of platinum, lead peroxid, magnetite, or similar substance, and removing the acetaldehyde by distillation, substantially as set forth.

6. The process of forming acetaldehyde which consists in combining ethylene with a mercury salt solution, sub ecting the compound thus formed to anodic' oxidation ire an electrolytic cell wherein the anode chamber and the cathode chamber are separated by a porous diaphragm, the cathode consisting of mercury or other suitable material, and removing the acetaldehyde by distillation, substantially as set forth.

7. The process of forming acetaldehyde which consists in combining ethylene with a mercury salt in the presence of a cerium anodic chamber of an electrolytic cell, subjecting the compound thus formed to anodic oxidation, and removing the acetaldehyde by distillation, substantially as set forth.

8.: The process of forming acetaldehyde which consists in combining ethylene with a mercury salt solution in an electrolytic cell, passing an electric current through the cell of the proper density and voltage, thus subjecting the compound to anodic oxidation,'and removin the acetaldehyde by distillation, substantially as set forth.

In witness whereof, I have hereunto set In hand and seal at Washington, District 0 Columbia, this twenty-ninth, day'of May, A. D. nineteen hundred and sixteen.

GEORGE O. CURME, JR. [1,. a]

Witnesses:

' E. W. Bnanronn,

Class. E. Broncos. 

